Setup:

The Lightning to USB Adapter is a passive adapter. This means that it does not emit energy to connected devices. A Lightning charging cable is therefore absolutely necessary to power the iOS device and the USB to LAN adapter.

Settings:

Check which network is used in WLAN, e. g. our network of 7 (ROM, MAILAND...)

So it is not allowed to use the 7th network for ethernet, otherwise you have either no internet or it doesn't print.

Here is a recommendation that we tested:

The entry Router and DNS can be skipped if the network is not extended via ethernet.